Aromatic amido-aldehyde and process of making same.



'NTTTLT) STATES PATENT QFFICE.

LORENZ ACH, OF MANNHEIM, GERMANY, ASSIGNOR TO 0. F. BOEHRINGER 82: SOEHNE, OF WALDHOF, GERMANY.

AROMATIC AMlDO-ALDEHYDE AND PROCESS OF MAKING SAME.

STECIFICATION formingpart of Letters Patent No. 667,382, dated February 5, 1901.

Original application filed January 21, 1899, Serial No. 702,955. Divided and this application filed October 28, 1899. Serial No.735,088. (Specimens) To all whom it may concern;

Be it known that I, LORENZ ACH, a citizen of the Empire of Germany, residing at Man nheim, in the Empire of Germany, (Whose post-oflice address is 0 1,) have invented certain new and usefullmprovements in Preparation of Aromatic Amido-Aldehydes; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to the preparation of amido-aldehydes, and in particular-the amidoaldehydes which are derivatives of aromatic series.

Pellizari has shown in Gazetta Ohimvlca, ItaZianct,Vol. 17 page 412 and seq., that products of addition maybe formed from alloxan and aromatic bases, and, further, by acting on these products of addition with alkalies he obtained acids which were poorer by one atom of carbon and one atom of nitrogen than the said products of addition. Now I have discovered in the course of my researches With reference to these compounds that both the addition products and the derivative acids may be converted into aromatic amido-aldehydes if they are heated with sulfuric acid or its equivalent, the conversion being attended by loss of oxygen and nitrogen. Both of these methods of obtaining these aromatic amido-aldehydes have been described in my application for Letters Patent of the United States, filed January 21,. 1899, Serial No. 702,955.

The present application, which is a divisional application from my said application No. 702,955, is designed to cover specifically the preparation of the aromatic amido-aldehydes from the acids of Pellizari-z'. e., the acids obtained from the addition of alloxau and aromatic bases, as above stated. Thus, for example, para-dimethyl-amido-benzaldehyde may be obtained if the acid obtained from the product of addition of dimethylanilin and alloxannamely, dimethyl-anilalloxan (O, II, N O described in Gazetta Ohimica ItalicmcaVol. 17, page 417, and Whose formula is C, H, N O ,be heated with sulfu- 5o ric acid. Under this process the amido-aldehydes are first obtained in sulfuric-acid solution from the free aldehydes, and may be readily separated by neutralization and subsequent extraction with ether or the like. This new process leads not only to'the primary, but also to the secondary and tertiary amidoaldehydes, and is susceptible of a very wide, extensive, and general application. It has accomplished this object when used in connection with all the benzene derivatives thus far treated. By varying the degree of concentration, the temperature,- and proportions of the sulfuric acid in accordance with the nature of the starting material employed the correct conditions for obtaining the amidoaldehydes in the most advantageous and economical manner are readily established.

My invention accordingly, broadly considered, consists in the treatment of the above derivative acids with heated sulfuric acid or its equivalent.

My invention, moreover, consists in such steps,features,and details of operation as will be set forth in the specification and pointed out in the claims.

In order to enable those skilled in the art to carryout my invention, I will now describe a number of examples which I consider the preferred embodiment of the said invention.

1. Preparation ofpara-dimethyZ-amido-benzaldehyde.0ne part of the acid G H N O of Pellizari is rapidly introduced into five parts of sulfuric acid of the specific gravity 1.8, which has been heated to 155 centigrade. The introduction is accompanied by agitation or stirring. The alloxan goes into solution attended by a violent evolution of gases. If, as I prefer, the temperature of the mixture is maintained at from 155 to 160 centigrade for ten minutes, the reaction will be completed at the expiration of that time, this completion of the reaction being indicated by the cessation of the evolution of gas. The solution so formed is then poured into ten parts, by volume, of cold water and neutralized with an alkali, such as soda. The resultant para-dimethyl-amido-benzaldehyde is then immediately separated in the form of shining foliated crystals. The crystals are separated by decanting or siphoning off the mother-liquor. The crystals are then taken up with ether, whereby they are extracted or separated from the portion of the liquor still adhering to them. The reaction proceeds according to the equation:

The yield is approximately theoretical. The degree of concentration of the sulfuric acid employed in this process may be varied greatly, although I find a sulfuric acid having a specific gravity between 1.5 and 1.84 gives the best results.

2. Preparation of para-dieth-yZ-amido-bertzaldehyde.0ne part of the acid obtained from diethyl-anilalloxan by acting thereon with alkalies according to Pellizari is introduced into five parts of sulfuric acid of the specific gravity 1.8 while stirring, the sulfuric acid having been heated to 155 centigrade. Solution takes place attended by a violent evolution of gas. After the lapse of ten minutes the solution is poured into ten parts of cold water, preferably at a temperature of 10 centigrade. The whole is then neutralized by an alkali, such as soda. The resultant aldehyde is then taken up with ether. The ether extract is then subjected to evaporation or allowed to evaporate, when the paradiethyl-amido-aldehyde remains as a rapidlyhardening oil, which has all the known characteristics set forth in Berichte der Deutschen Ohemt'schen Gesellschaft, Vol. 19, page 396. The reaction proceeds according to the equation:

is is e e+ 2 3. Pre aratt'on 0f para-methyZ-amido-benzaZdehyd ;.One part of the acid C I-I l\T O, derived from methyl-anilalloxan by acting thereon with alkalies according to Pellizari is introduced into five parts of sulfuric acid of the specific gravity 1.8 and heated to 155 Centigrade While stirring. After the lapse of about seven minutes the resulting solution is poured into ten parts of cold water. The whole is then neutralized with alkali, such as soda, and the resultant aldehyde is extracted with ether, as in the preceding ex-' amples. After the evaporation of the ether therefrom the methyl amido benzaldehyde remains as an oil, which gradually solidifies in crystalline form. The reaction proceeds according to the equation:

It is purified by distilling with superheated steam. Under this treatment the aldehyde goes over in the form of a yellow oil, which rapidly crystallizes in the form of small lustrous plates or scales. It is readily soluble even in the cold in the usual organic solvents, but

less so in ligroin. From water it crystallizes in the form of rhombic plates having the melting-point to 61 centigrade. Its formula is:

NH.CH i/\ 4. Preparation of para-ethyl-amido-benzaldehyde.0ne part of the derivative acid from ethylanilalloxan according to Pellizari is introduced intoseven parts of sulfuric acid of the specific gravity 1.8 heated to 160 centigrade, the acid being stirred at the same time. The evolution of gas which takes place ceases at the end of about seven minutes. The resultant solution is then pouredinto ten parts of water of a temperature of about 10 centigrade. The whole is then again neutralized with an alkali, such as soda, and the aldehyde taken up with ether, as in the preceding examples. After the ether has evaporated off the aldehyde remains as a rapidly-solidifying oil. This oil is then distilled with superheated steam, the aldehyde going over and collecting as a yellow oily substance, which crystallizes rapidly on cooling. The reaction takes place according to the equation:

darker color when exposed to light. Its formula is 5. Preparation of para-amido-benzaldehyde.0ne part of the acid C H N O which has been described in Gazetia O'himz'ca Ital ia'na, Vol. 17, page 4:13, and which is derived from anilalloxan according to the method above set forth, is rapidly introduced into nine parts of sulfuric acid while constantly agitating or stirring the same. The sulfuric acid employed is preferably of the specific gravity 1.83 and must be previously heated to from 160" to 170 centigrade. The ensu ing evolution of gases is terminated after from ten to fifteen minutes, and thereupon the mixture is poured into about ten parts, by volume, of water. On gently warming the Whole a clear solution results, which on further heating becomes continually lighter in color. The solution should not be heated above centigrade and this heat should be continued for some tlme. The solution is then allowed to cool, when it again acquires a darker color until finally a dark-red salt is separated. The reaction takes place according to the equation:

compound by polymerization. Its formula is.

OH O

6. Preparation of para-amido-meta-tolaylaldeh ycZe.One part of the acid derived from ortho-toluidyl-alloxan according to Pellizari is introduced into seven parts of sulfuric acid of the specific gravity 1. 8,which has been heated to 160 centigrade. The introduction is accompanied .by stirring and gives rise to strong foaming and after a short time solution takes place. The whole is poured into ten parts of water of a temperature of about 10 centigrade. The mixture is again neutralized, preferably with soda, and the resultant aldehyde is extracted with ether. After evaporating the ether the para-amido-metatoluylaldehyde remains as an oily substance, which solidifies to a crystalline mass within a few minutes. The reaction takes place according to the equation:

This aldehyde softens somewhat on heating over ceutigrade and melts at from 99 to 100 centigrade. It is soluble in alcohol and ether and with greater difficulty in hot water. It readily changes to a polymeric insoluble form and in'other respects it exhibits great similarity with the para-amidobenzaldehyde, described in German Patent No. 87,255 to Geigy and Cie, of Basle. Its formula is CH O 7. Preparation of para-mnido-meta-meihoxy-benzaldehyde.One part of the acid derived from auisidil-alloxan according to Pellizari is introduced into and agitated with seven parts of sulfuric acid of specific gravity 1.8, which has been heated to 160 centigrade.

After the lapse of about five minutes the resultant soiution is poured into ten parts of water of a temperature of about 15 centigrade, and the Whole is again neutralized with an alkali, such as soda. The resultant aldehyde is again extracted with ether. After evaporating the other from the extract the al dehyde remains in the form of a slightly-colored crystalline mass,which, however, rapidly becomes dark red. The reaction takcsplace according to the equation:

The aldehyde is purified and bleached by dissolving in warm benzene, in which the coloring-matter is soluble only with difficulty. Petroleum etheris then added in sufficient quantity to completely precipitate the aldehyde. The para-amido-meta-methoxy-benzaldehyde so precipitated forms yellow accicular crys tals, which melt at 101 to 102 centigrade. This aldehyde is very sensitive to light. Its formula is I I Jocn,

CHO

What I claim, and desire to secure by Letters Patent of the United States, is-

1. The process of preparing aromatic amidobenzaldehydes, which consists in treating with a mineral acid the herein-described acid of Pellizari derived from alloXan and an aromatic base.

2. The process of preparing aromatic amidobenzaldehydes which consists in heating with sulfuric acid an acid derived from a product of addition of alloxan with an aromatic base, according to Pellizari.

3. The process of preparing aromatic amidobenzaldehydes which consists in adding a deloxan with an aromatic base to heated sulfuric acid and stirring, allowing to stand, and then pouringinto water,all in the proportions, substantially as set forth.

4. The process of preparing aromatic amidobenzaldehydes which consists in adding to heated sulfuric acid an acid derived according to Pellizari from a product of addition of alloxan with an aromatic base and stirring, allowing to stand, pouring into water, and. finally neutralizing with alkali, all in the proportions, substantially as set forth.

5. The process of preparing aromatic amidobenzaldehydes which consists in adding to heated sulfuric acid an acid derived according to Pellizari from a product of addition of alloxan with an aromatic base and stirring, allowing to stand, pouring into water, then neutralizing with alkali and extracting the resultant new compound with ether.

6. The process of preparing aromatic amido- ICO rived acid from a product of addition of albenzaldehydes which consists in adding to heated sulfuric acid an acid derived according to Pellizari from a product of addition of alloxan with an aromatic base and stirring, allowing to stand, pouring into Water, then neutralizing with alkali and extracting the resultant new compound with ether, then evaporating the ether and distilling the residual new compound with superheated steam.

7. The process of preparing aromatic amidoaldehydes which consists in heating with sulfuric acid the acid derived from toluidyl-alloxan by treatment with alkali.

8. The processofpreparingaromaticamidoaldehydes Which consists in adding to heated sulfuric acid the acid derived from toluidylalloxan by treatment with alkali and stirring and then after evolution of gas has ceased pouring the whole into water.

9. The process of preparing aromatic amidoaldehydes which consists in adding to heated sulfuric acid an acid derived from toluidylalloxan by treatment with alkali and stirring and then after evolution of gas has ceased pouring the whole into water, and finally eX- tracting the new compound wit-h ether.

10. The process of preparing aromatic amido-aldehydes which consists in adding an'acid derived from toluidyl-alloxan by treatment with alkali to heated sulfuric acid and stir ringand then after evolution of gas has ceased, pouring the whole into water, then extracting the resultant compound with ether and, finally distilling the same withsuperheated steam.

11. As a new chemical compound paraamido-toluyl-aldehyde having the formula above given, whose melting-point is from 99 to 100, centigrade, which issoluble in alcohol and ether and with greater difficulty in hot water.

In testimony whereof I affix my signature in presence of two witnesses.

' LORENZ AOH.

Witnesses:

FRITZ AoH, JACOB ADRIAN. 

